I was having the same fail/mistake but in Ubuntu 18.04 (Gnome and vanilla desktop), I don't know why but since 2 weeks ago (since an update of gnome-control-center I think, but I'm not sure) the lock screen just doesn't work and neither the settings, it's like zhiwei said, it doesn't allow any changes.
But doing this: "gsettings set org.gnome.desktop.lockdown disable-lock-screen false" Now works. Thanks, srsly. I was searching since two weeks without any results. I add this comment if anyone has this fail too. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/864458 Title: screensaver doesn't work To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/864458/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
